A liquid crystal display panel is generally constituted by cell assembling a color filter substrate and an array substrate with a liquid crystal layer sealed therebetween. As a liquid crystal molecule itself does not emit light, a display requires a light source for image displaying. A liquid crystal display can be categorized as a transmissive type, a reflective type, or a transflective type, based on the adopted types of the light source.
The transmissive type liquid crystal display mainly employs a backlight as the light source disposed behind the liquid crystal panel. The pixel electrode on the array substrate is a transparent electrode, used as a transmissive region, which facilitates light from the backlight to transmit through the liquid crystal layer to display images. The reflective type liquid crystal display mainly employs a front light or an exterior light as the light source, metal or other materials with excellent reflective properties is disposed on the array substrate as a reflective region, suitable for reflecting the light from the front light or the exterior light. The transflective type liquid crystal display can be deemed as a combination of the transmissive type and the reflective type, where both the reflective region and the transmissive region are disposed on the array substrate, and both the backlight and the front light or the exterior light are used for image displaying.
The transmissive type liquid crystal display (LCD) has an advantage of being able to display a bright image in a dark environment; nevertheless, it has the disadvantage that only a low percentage of light from the backlight is transmitted, meaning a low utilization rate of the backlight. Improving the display brightness demands significantly raising the luminance of the backlight, necessitating high energy consumption.
The reflective type LCD has the advantage of being able to use sun light or front light source as the light source, and thus has relatively low energy consumption; it, however, cannot display an image in a dark environment, due to the dependency on exterior light.
The transflective type liquid crystal display combines the advantages of the transmissive type and the reflective type liquid crystal panels, which can display a bright image in a dark environment, and can be used indoor or outdoor; therefore, it is widely used to display devices of electronic products, such as, mobile products such as mobile phone, digital camera, handheld computer, GPRS.